An engine, such as a marine engine, may employ a rubber primer bulb type pumping device to provide initial prime to the fuel supply system. Such devices are simple rubber bulbs connected to fuel hoses and with a set of one-way valves to direct the direction of pumping when the bulb is squeezed.
The used primer bulb type pumping device may be disclosed in U.S. Pat. No. 8,834,137. A pump is disclosed and includes a substantially tubular housing having an inlet end and an outlet end and defining a central axis and a chamber within the body portion, and a movable valve assembly slidably received within the housing for movement in the direction of the central axis. The pump also includes a handle assembly slidably disposed at least partially around an outer circumference of the housing for movement in the direction of the central axis, the handle assembly being substantially annular ring-shaped, and the handle assembly including a grip engageable by a hand of an operator for manually sliding the handle assembly, the handle assembly being coupled to the movable valve assembly, manual movement of the handle assembly along the central axis causing corresponding movement on the movable valve assembly along the central axis.
However, the structure of the conventional primer bulb type pumping device is complicated and then make the manufacturing method is multi-stage and wasting time. Further, the production yield may be limited.